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Subject: Re: [PATCH v14 06/13] iommu/smmuv3: Allow stage 1 invalidation with
 unmanaged ASIDs
To:     Zenghui Yu <yuzenghui@huawei.com>
Cc:     eric.auger.pro@gmail.com, iommu@lists.linux-foundation.org,
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References: <20210223205634.604221-1-eric.auger@redhat.com>
 <20210223205634.604221-7-eric.auger@redhat.com>
 <7a270196-2a8d-1b23-ee5f-f977c53d2134@huawei.com>
From:   Auger Eric <eric.auger@redhat.com>
Message-ID: <8350e4e2-4607-cfd7-b1a7-1470bf18da6d@redhat.com>
Date:   Thu, 1 Apr 2021 11:38:16 +0200
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Hi Zenghui,

On 3/30/21 11:17 AM, Zenghui Yu wrote:
> On 2021/2/24 4:56, Eric Auger wrote:
>> @@ -1936,7 +1950,12 @@ static void
>> arm_smmu_tlb_inv_range_domain(unsigned long iova, size_t size,
>>           },
>>       };
>>   -    if (smmu_domain->stage == ARM_SMMU_DOMAIN_S1) {
>> +    if (ext_asid >= 0) {  /* guest stage 1 invalidation */
>> +        cmd.opcode    = smmu_domain->smmu->features &
>> ARM_SMMU_FEAT_E2H ?
>> +                  CMDQ_OP_TLBI_EL2_VA : CMDQ_OP_TLBI_NH_VA;
> 
> If I understand it correctly, the true nested mode effectively gives us
> a *NS-EL1* StreamWorld. We should therefore use CMDQ_OP_TLBI_NH_VA to
> invalidate the stage-1 NS-EL1 entries, no matter E2H is selected or not.
> 

Yes at the moment you're right. Support for nested virt may induce some
changes here but we are not there. I will fix it and add a comment.
Thank you!

Best Regards

Eric